Is Faith Harmless?

Short answer: No.

If you'll allow me to steal from Peter Boghossian, faith is a broken epistemology, it's a way of pretending you know something you don't really know.

Epistemology is the way you know things. Faith allows people to claim to know things they don't. Faith is the buttress for claims from the mild to the asinine, from the irritating to the debilitating, to deadly. It is the exact same process that Catholics use to believe a cracker becomes the actual, physical body of the risen savior that Jews use to justify mutilating infant genitalia, that Muslims use to bomb churches. There is no difference.

Many have argued that secularists, humanists, antitheists should spend their time on the latter two and ignore the former as harmless. They definitely have a point that shouldn't be ignored. We are a minority and we only have so much time, money, and energy. We're also nowhere near as united as the forces of irrationality that give credence to faith. We need to invest our efforts where they're most valuable.

However, I don't think we should ignore the crackers. PZ Myers desecrated a communion wafer that he received from a student who smuggled it out of a service for him. Both Myers and the student received death threats, as well as Myers's university was flooded with letters demanding he be fired. Clearly, this isn't a small issue for the Catholic League.

With this example, I wish to demonstrate two things:

1. Clearly, this is the same faith. Myers's minor act of desecration against a minor tenet of faith received a response out of all proportion. His university was flooded with letters and even now, five years later, they're still receiving mail about the incident. Through the lens of faith, there is no difference between this and the more "serious" acts of faith.
2. I believe that there is a more practical connection between these. The "minor" acts of faith give legitimacy to the more ridiculous tenets. That no one really cares to question the small things that don't matter, but this means that, with faith allowed a leg to stand on, the more absurd beliefs can point to those and say, "See? These are fine!" And then they turn around with Matthew 23:24

You blind guides, who strain out a gnat and swallow a camel!

The smaller faiths give legitimacy to the larger, which turn around and give legitimacy to the smaller. The edifice demands you dismantle the entirety all at once, bootstrapping itself on nothingness all the while.

In answer to the argument from practicality, that we have bigger fish to fry, I offer this: the smaller faith takes less time and energy to ridicule. Spend a few moments ridiculing their weekly ritual cannibalism, point out that they believe not simply absurdities, but foolish, childish absurdities:

Every week you go to a sing-song and promise yourself in slavery to a cosmic zombie because a rib-woman was convinced to eat a magic fruit by a talking snake, which broke the universe, and then God needed blood to fix the universe, but only his own blood had enough magic so he raped a virgin to give himself a body and killed it. 

All faith is bad. All faith is equal. All faith is equally harmful. Some particular instances of faith just happen not to be harming people at this particular moment. 500 years ago those angry Catholics wouldn't have stopped at threatening to kill PZ Myers. He'd be rather horrifically dead.